1. Field of the Invention
This invention pertains broadly to the field of separation fasteners. More particularly, the invention pertains to separation fasteners utilizing gas pressure. In still greater particularity, but without limitation thereto, the invention pertains to a gas pressure shear separation fastener suitable for use in small confines and where sealing of the fastener after separation is desired.
2. Description of the Prior Art
Separable fasteners are well known in the fastener art. Generally, these fasteners can be broken into one of several categories: those which are separated by tensile forces, those which are separated by shear forces and those separated by pressure overload forces. In these categories, both explosives as well as gas generators have been used to generate the necessary forces for separation.
In cases in which an explosive is used, the pressure wave caused by the explosion can do more than merely separate the fastener. The explosion can cause portions of the bolt body to disintegrate thereby propelling shrapnel into nearby instruments, structures and/or people. Furthermore, the shock of the explosion can damage sensitive equipment or components. In instances where gas generators are utilized a more controlled separation is possible, however oftentimes gas generator separation fasteners incorporate pistons or plungers that occupy a relatively large amount of space.
In either tensile, shear, explosive or gas generating fasteners, separation of the fasteners can leave a path through which fluids may travel. In underwater environments, for example, such a path poses obvious hazards.